Purging system for refrigerating systems



Get. 5, 3%48. J. R. zwlCKL PURGING SYSTEM PoR REFRIGERATLING swsmxsV 3 Sheets-Sheet, 1

Filed June 6, 194,15

INVENTOR ATTORN EY @t 5, E948. J. R'zwlcKl.

PURGING SYSTEM FOR REFRIGERATING SYSTEMS 3 Sheets-Sheet 2 Filed June 6, 1945 ATTORNEY 0d 5, 1948. J. R. zwlcKl.

PURGING SYSTEM FOR REFRIGERATING SYSTEMS 3 Sheets-Sheet 3 INV ENTOR ATTORN EY Patented Oct. 5, 1948 PURGING SYSTEM FOR REFRIGERATING SYSTEMS Joseph R. Zwickl, East Orange, N. J., assignor to Worthington Pump and Machinery Corporation, Harrison, N. J., a corporation of Delaware Application June 6, 1945, Serial No. 5977,849

19 Claims. 1

This invention relates to refrigeration sys.

tems, and more particularly to purging systems and apparatus for use in refrigerating systems.

The present invention is particularly adapted for use in closed refrigeration systems wherein a refrigerant, such as those of the Freon class, is circulated through a closed system embodying an evaporator or cooler, a compressor, and a condenser. If such systems operate below atmospheric pressures, they are subject to in-leakage of air with its contained water vapor which causes pollution or fouling of the refrigerant. Such pollution or fouling of the refrigerant interferes with the effectiveness of the system, and hence it is desirable, even necessary, to remove these polluting agents from the refrigerant in the system and maintain the refrigerant in as great a degree of purity as is possible so as to insure maximum effectiveness of the operation of the system.

The present invention comprehends a purge system for use in such closed refrigerating systems, including rst strip means for separating the larger percent of the condensible refrigerant vapor carried along with .the air and foul gases to the purge system from the main condenser; the

compressing of the stripped foul gases, separation of oil from the compressed vapor and noncondensible gases, a final strip means through which the compressed gases and vapor are passed to finally strip practically all condensibles from the gases, and suitable means for separating the condensed water vapor from the condensed refrigerant vapor, with the return of the condensed refrigerant vapor to the system for recirculation, while the water and noncondensibles are drawn out of the system.

Heretofore in purging from closed refrigerating systems the pollution agents such as oil, air, and water, the practice has been to pass the refrigerant vapor containing the gases and water vapor direct from the main condenser to the purge compressor where the mixture of vapors and gases were compressed, and subsequently such oil as'was picked up by the refrigerant during its passage through the system and duringfits'compression was separated from the mixture of vapor and gas, and the vapor was then condensed.

However, it has been found that, due to peculiar conditions met with in such refrigerating systems. particularly where certain types of refrigerant are employed, refrigerant vapor con-L taining only a small percent of noncondensible or foul gas can not be compressed in a small purge compressor to the high pressures needed for efficient purging of the system without condensation of some of the refrigerant vapor in the cylinder or cylinders of the purge compressor. As a result of such condensation in the cylinder of the compressor, the lubricating oil on the cylinder'walls is washed off by the condensing refrigerant, resulting in undulyv and undesirable rapid wear on the piston rings of the compressor; also some of the condensed refrigerant will find its way into the crank case of the compressor and dilute the lubricating oil therein, causing a foaming of the oil when under reduced pressure, with the consequent loss of lubricating oil and ineffective lubrication of the compressor parts.

To prevent this undesired condensation in the purge compressor, which in a short time detrimentally affects the efficiency of ythe entire system through failure of proper purging, the present invention comprehends the provision of a purge system wherein the greater part of the refrigerant vapor is condensed and removed from the mixture of vapor and vgas drawn from the main condenser of the system, before this vapor and gas mixture is compressed, thereby greatly reduc ing the percent ratio of refrigerant vapor to noncondensible gas in the mixture which is passed to the 'compressor for compression. This reduction of the percent ratio of refrigerant vapor to noncondensible gas in the mixture greatly reduces or prevents the condensation of condensible vapors in the purge compressor, with a resultant removal l of the detrimental effects of such condensation from the operation of the system.

with these and other objects in view, as may appear from the accompanying speciiflcation,fthe

invention consists of various features"y ofe911struc-t tion and combination of parts, which will be rst described in connection with the accompanyingy drawings, showing a purging system for refrigerating systems of a preferred formembodying the inventionVandthe fea-turesforming the in Figure 4 is a diagrammatic view partly in section of a modified form of the purging system. Referring more particularly to the drawings, a closed refrigeration system of the type embodying a centrifugal compressor I, a condenser 2,-an

to be cooled is circulated through the tubes of the evaporator. If such systems operate below atmospheric pressure, they are subject to inleakage of air with its contained water vapor which causes pollution or fouling of the refrigerant. Then also, duringits circulation through the refrigerant system and through the purge system which co-operates therewith, the refrigerant may pick up lubricating oil which also has a detrimental action on the effectiveness of the operation of the system.

The noncondensible gases mixed with refrigerant vapor accumulate in the top of the condenser 2 and are taken off the top of the condenser 2 through a suitable pipe connection I0 which delivers such mixture of vapors and gases to the purge system. The pipe Il) has a. valve I I interposed therein by means of which the flow of the mixture of noncondensible and uncondensed vapor to the purge system may be controlled. This valve is operated during the starting up period of the purge system as a throttle valve until the purge system fills sufficiently with foul or noncondensible gas so as to prevent its flooding by too rapid condensation. After the purge system is sufficiently filled with noncondensible gas, the valve I I is opened to such degree as to permit free flow of the mixture of noncondensible gases and refrigerant vapor into the purging system, without overloading its capacity.

The pipe Ill delivers the noncondensible gas and refrigerant vapor mixture to a pipe coil I2 which extends vertically in the inner shell I3 of the purge drum structure I4. The annular chamber within the inner shell I3 is filled with liquid refrigerant in the manner which will be hereinafter described, and is connected by means of suitable piping I5 with the evaporator 4 so that theliquid refrigerant within the inner shell I3 is essentially at the same pressure and temperadesired, a bulls eye or transparent eye, as indicated at I 1, may be placed in` the pipe or line I5 so as to permit visual observance of the liquidflowing through the line I5 so as. to ascertain that sufficienty liquid refrigerant lpasses through the inner or coil chamber I3 to insure' that'the coils thereinare totally submerged in the coldA liquid refrigerant.

As the mixture of the noncondensible gases vand the condensible vapors, including refrigerant vapor and water vapor passesthrough the coil I2 which is chilled by the liquid refrigerant surrounding it, the refrigerant'.l and water vapors,

lorvat least the major portion of tlienl,y will be condensed; whereas, the noncondensibles will naturally remain uncondensed. The condensate, that is, the condensed refrigerant. and Water vapor, flows from the outlet end I8 of the coil l2 upon an annular spill plate I9 located in the separation portion Yof the purge drum I4. As clearly shown in Figure 2 of the drawings, the separation portion of the purge drum I4 is positioned below the condensing or coil-containing portion of the drum I4. The mixed condensate flows over the circular Weir 20 upon a distribution plate 2I and into the annular separation space 22. In the annular separation space 22, the water, being lighter than the condensed refrigerant, rises to the top of the mixture and flows through the opening 23 into the central water-containing portion 24, while the liquid refrigerant passes from the lower portion of the annular separating space 22 through a riser pipe 25 into the annular refrigerant storage space 26 in the separation portion of the purge drum I4. The liquid refrigerant is discharged from the refrigerant storage space 26 through a suitable pipe line 21 into the bottom of the inner or coilcontaining shell I3 of the purge drum. The flow of the refrigerant from the storage space 26 is controlled by a solenoid-actuated valve 28 of any approved construction which may be purchased upon the open market. The energizing of the solenoid 29 of the solenoid-actuated valve structure 28 is in turn controlled by a float operated electrical switch structure 30 of any approved type which may be purchased upon the open market. The float actuated switch structure 30 is connected to the chamber 26 so that the float 3| of said structure moves under variances of the level of the refrigerant in the storage space 26 for opening or closing the valve 28, and, consequently, controlling the flow ofthe liquid refrigerant from the chamber 26 into the shell I3.

Since the liquid refrigerant supplied to the shell I3 from the annular storage space 26 is insufflcient to submerge the coil I2, a make-up quantity of refrigerant is delivered from the main condenser 2 of the refrigerating system through a makeup pipe 32 and control needle valve 33, and thus suicient liquid refrigerant may be circulated through the shell I3 at all times to maintain the coil I2 submerged.

The noncondensble gases with such relatively small percentage of the refrigerant and water vapors as are not condensed in the coil I2 flow out at the end of the coil with the condensate, and they, together with any gases or vapors which might be separated from the condensation in the lower separation portion of the purge drum I4, pass upwardly through the annular space 34 formed between the inner shell I3 and the outer shell 35 of the purge drum structure.

Restricting ori-ces are provided at the outlet of the annular space 34 as shown at 38, and the non-condensed Igases and vapors pass through the restricted orifices 36 into the space 31 at the top of the drum I4. T he annular space 34 has vertically extending, substantially radial fins 33 extending therethrough (as clearly shown in Flgure 3 of the drawings) which -are preferably soldered orwelded to the inner 'shell I3 and serve ito"strengthen'the inner shell against collapsing, since the pressure inside the shell is substantially the same as the pressure within the evaporator 4,

and also to materiallyv enlarge the heat transfer surface of the inner shell 3, and, consequently. venhance or increase the heat transfer action between the cold shell (chilled by the liquid refrigerant therein) and the noncondensible gases with such condensible vapors as are still mixed therewith during their passage through the annular space 34, thus promoting land .providing a stripdownwardly therein :to the spill plate I9 and over-` ow therefrom for separation of the water from the refrigerant in the manner heretofore described. y

The space 31 in the top of the outer shell 35 of the purge drum I4 is connected Iby suitable piping indicated at 40 with a collecting tank 4| for .the foul or noncondensible gas. A difierential pressure bleeder valve 42 of any approved construction which may be obtained on the open market is located in the piping 40 for allowing the noncondensible gases to ow to the tank 4I and prevent back fiow of said 'gases to the space 31. This valve 42 is set so as to maintain in space 34 a pressure, which is always lower than the pressure in the main condenser 2, but only by such a differential as is required to maintain a suicient ow of gas from the condenser 2 into the purger. It is essential to hold the .pressure in space 34 as high as possible, because the higher this pressure the better will be the stripping action on the gas mixture as it drifts through space 34 along the chilled outer surface of shell I3. 'Ilhe condensing of the condensible vapors from the mixture of foul gas and'vapor delivered to the coil I2 from the condenser 2 will very materially reduce the quantity of the mixture of gas and vapor flowing to the tank 4|, and will, of course, very materially reduce the percentage of condensible vapors contained in the mixture. When the pressure of the stored mixture of gas and vapor in t'he tank 4I reaches a predetermined degree the pressure actuated switch 43 in the suctionline to the purge compressor 44 will be opened to allow the compressor to draw ygas and vapor mixture from the tank 4| until such time as the pressure in the tank falls below the degree required to operate the pressure switch 43.

The pressure actuated switch structure 43 is of an approved type which lhas long been known to the refrigeration artand which may be purchased `upon the open market. The pressure actuated switch 43 starts -the prime mover of the compressor 4'4, and the gas drawn from the tank 4| by the compressor 44 is -compressed and discharged tlhrough the discharge line `45 of the compressor `through a check -valve 46 into an oil collector or separator 41. The oil which may be picked up by the mixture of noncondensible gas and condensible vapors in the compressor 44 separates ou-t from the compressed mixture in the oil collector 41 and is returned to the crank case 48 of the -compressor through a suitable connecting line 49. The compressed mixture passes from 4the oil separator 41 through a suitable piping 50 and enters a second or inner coil 5I inthe inner or coil-containing shell I3 of the purge drum I4". If it is so desired, and if the quantity of oil pi-cked up during the Icompression of the mixture is negligibly low, the oi'l separator 41 may be eliminated and the compressed` mixture pas-sed directly through the line 50 to the inner -coil 5I.

rPhe inner coil 5I, like the coil I2, is submerged in cold liquid refrigerant within the shell I3 and any condensible vapors, which might be contained in the compressed Imixture delivered to the coil. are condensed during the passage of the compressed mixture through the inner coil 5I. The noncondensible gas and any vapor condensed in the inner coil 5| passes from the outlet end 52 of the coil into the inner most chamber 53 with the coil-containing chamber or inner shell I3. The condensate from the coil 5I accumulates in the bottom of the chamber 53, and when a sufficient quantity thereof accumulates to move the oat 54, the valve 55 will be operated by the float, 4allowing such condensate to'pass out into the inner shell I3 and out of this shell I3 through the line I5 to the evaporator 4. The noncondensible gas accumulates in the top of the chamber 53 and is bled therefrom through an outlet pipe 56 in which is located a solenoid actuated valve 51. The energizing of the solenoid 58 of the soleniod operated valve structure 51 is controlled by a pressure actuated switch structure 59 which may be of Iany approved construction and is connected in the outlet pipe 56 so that the valve 51 will only be opened when the pressure of the noncondensible gases in the chamber 53 reaches a predetermined degree. The noncondensible Vgases are vented to atmosphere or to any suitable place (not shown), and if it is so desired, a pressure reducing orifice 60 may be connected in the outlet pipe 56 beyond the solenoid actuated valve 51.

In order to prevent any condensation in the cylinders or cylinder head of the compressor 44 when 'the compressor stops operating, and thus cools down, a by-pass line 6I is provided between the compressor inlet and discharge, and this line has a solenoid actuated valve structure 62 connected therein, the solenoid 63 of which is inter- -connected with the circuit of the motor (not shown) which operates the compressor 44, so that when the compressor 44 is running the valve 62 is closed, and when the 4compressor stops, the

valve 62 will be opened to permit the reexpanding` of the already compressed gas and vapor mixture which is in the compressor head and the line 45 up to Ithe check valve,l 46. Since the dew point of this gas Iand vapor mixture is low there can be no condensation before the check valve 46, if the pressure is lowered properly.

With the arrangement and system shown in the drawings and described herein, the purge compressor 44 runs only when the accumulation of the gas vand vapor mixture in they tank 4 I reaches a degree Where its pressure is suflicient to operate the pressure actuated switch 43, thus materially increasing the life of the compressor. The improved purge system herein set forth pro- .Vides for a continuous removal of water from the system regardless and independent of operation of the purge compressor 44, because the pressure differential, causing the ow of gas from the main condenser 2 to the purge drum I4 is continuously maintained by the diiferential p ressure bleeder valve 42 between the purge drum I4 and foul gas collecting tank 4I. Also any condensar tion of vapor in the compressor with its resultant disadvantages as previously pointed out is eliminated.

A sight glass 10 is connected in a looped pipe 1I which has communication with the watercontaining space 24 in the separator structure, and by means of the level of water in the sight glass 10, the quantity of water in the vspace 24 may be readily determined. When the quantity of'water in the space `24 rises to such a height as to be apt to interfere with the operation of the the drawings and described herein above will purge the refrigerating system only when the refrigeration system is in operation, and will not purge the refrigeration system of noncondenslbles when the system stands, or is not in operation, with equalized pressure in evaporator I and the condenser 2.

Figure 4 of the drawings shows a modiilcation of the improved purge system whereby the refrigeration system may be purged of noncondensibles, while the refrigerating system stands with .equalized pressure in the evaporator and condenser, or in starting the refrigeration system.

In the modified form shown in Figure 4 of the drawings a bypass is connected in the piping 40' around the differential pressure bleeder valve 42'. A normally operated valve lili is located in the bypass 00. When the valve ilii is open the purge compressor M' is connected to the main condenser (not shown) of the refrigeratlng system through the collecting tank I I and the purge drum i4' so that the compressor may continuously pump a mixture of air, refrigerant vapor etc., from the refrigeration system.

In order to separate the air of foul gases from the mixture drawn from the refrigeration system by the compressor M it is necessary to condense the condensibles in the compressed mixture. Since no liquid refrigerant is available in the purge drum il', at such times, for this condensing action an air cooled coil condenser |03 is connected in the piping or line 50 between the oil` collector 41 and the inner coil 5i' of the purge drum structure il. The air cooled condenser coil i may be cooled by a fan |04.

The condensate and noncondensibles flow from the air cooled coil condenser |03 into and through the inner coil il', passing from the outlet 62' of the coil 5| into the inner chamber $3' where the condensate and the noncondensibles separate.

When the pressure in the inner chamber 53' reaches a sufllciently high degree to cause operation of the solenoid actuated valve 51' the noncondensibles will be discharged through the outlet pipe It'. When the level of the condensate in the inner chamber $3' reaches a suiiicient height to operate the float actuated valve 5l' the condensate is discharged upon the annular spill plate I9' in the separation portion oi' the purge drum il' and from there into the separating space 22' wherein the refrigerant and water are separated in the manner described in connection with Figures i to 3 of the drawings. The separated out water is disposed of and the liquid refrigerant is returned to the refrigerating system in the same manner as described in connection with the system described above and shown in Figures 1 to 3 of the drawings.

During the normal operation of the refrigeration system the valve ill is closed and the air cooled condenser |03 acts simply as a preliminary condenser so that less condensing will have to be done in the inner oii 5I of the purge drum il.

It will be understood that the invention is not to be limited to the specific construction or arrangement of parts shown, but that they may be widely modied within the invention defined by the claims.

What is claimed is:

l. The method of purging a closed refrigeration system containing a volatile refrigerant and including a condenser and an evaporator, of polluting agents such as air, water and oil which comprises taking from the condenser` uncondensed refrigerant and water vapor mixed with noncondensible gases and subjecting the mixture to a temperature lower than the temperature in the condenser, which lower temperature is produced by evaporation of refrigerant at a lower pressure so as to condense the greaterquantity of condensible vapors in the mixture, collecting the residual mixture of noncondensibles and condensible vapor not condensed by said first condensing action, taking off a part of the collected mixture when its pressure reaches a predetermined degree, compressing the taken oi part of f the mixture, separating oil from the compressed mixture, subjecting the remaining compressed mixture to condensing temperature sumciently low to condense practically all of the condensible vapors in the mixture, separating the condensed water vapor from the condensed refrigerant vapor, and returning the condensed refrigerant vapor as liquid to the system.

2. The method of purging a closed refrigeration system containing a volatile refrigerant and including a condenser and an evaporator of polluting agents such as air, water and oil, which comprises taking from the condenser uncondensed refrigerant and water vapor mixed with noncondensible gases and subjecting the mixture to a temperature lower than the temperature in the condenser so as to condense the greater quantty of the condensible vapors in the mixture, compressing the non-condensed residual mixture, separating oil from the compressed mixture. subi jectng the remaining compressed mixture to condensing temperature sufllciently low so as to condense practically all of the condensible vapors therein, separating the condensed water vapor from the condensed refrigerant vapor and returningthe condensed refrigerant vapor to the system.

3. The method of purging a closed refrigeration system containing a volatile refrigerant and including a condenser and an evaporator of polluting agents such as air, water and oil. which comprises taking from the condenser uncondensed refrigerantA and water vapor mixed with noncondensible gases and subjecting the mixture to a temperature lower than the temperature in the condenser so as to condense the greater quantity of the condensible vapors in the mixture, compressing the non-condensed residual mixture, separating oil from the compressed mixture. subjecting the remaining compressed mixture to condensing temperature sufficiently low so as to condense practically all of the condensible vapors therein. separating the condensed water vapor from the condensed refrigerant vapor, utilizing densed refrigerant and water vapor mixed with c noncondensible gases and subjecting the mixture i to a temperature lower than the temperature in" the condenser so as to condense the greater quantity of condensible vapors in the mixture,

collecting the residual mixture not condensed by said first condensing action, taking of! a part o1 the collected mixture when its pressure reaches a predetermined degree, compressing the taken off part of the mixture, separating oil from the compressed mixture, subjecting said residual mixture to condensing temperature sufllciently low to condense practically all of the condensible vapors in the mixture, separating the condensed water vapor from the condensed refrigerant vapor, utilizing the condensed refrigerant vapor as a cooling medium in the vapor condensing steps and finally returning the condensed refrigerant vapor as liquid to the system.

5. In a refrigerating system containing a volatile refrigerant and including a condenser and an eva-porator, means for purging the system of noncondensibles and polluting condensibles including a separator structure, a condensing coil in said separator structure, means for delivering noncondensible gas mixed with condensible vapors from the condenser to said coil, means for separating water and liquid refrigerant condensed in said coil, and .means for returning the liquid refrigerant from said separating means into contact with the outside of the coil where it acts as a `coolant to condense the condensible vapors passing through the coil.

6. In a refrigerating system containing a volatile refrigerant and including a condenser and an evaporator, means for purging the system of noncondensibles and polluting condensibles including a separator structure, a condensing coil in said separator structure, means for delivering noncondensible gas mixed with condensible vapors from the condenser to said coil, means for separating Water and liquid refrigerant condensed in said coil, a storage tank, means for delivering mixed non-condensed vapor and noncondensible gas from said coil to said storage tank, a cornpressor, means for delivering mixed vapor and noncondensible gas from said tank to said compressor, and means for delivering the compressed mixture from the compresser to 'said separator structure for final condensation of any condensible vapor contained inthe mixture.

'7. In a refrigerating system containing a volatile refrigerant and includingA a condenser and an evaporator, means for purging the system of noncondensibles and polluting condensibles including a separator structure, a condensing coil in said separator structure, means for delivering noncondensible gas mixed with condensible vapors from the condenser to said coil, means for separating Water and liquid refrigerant condensed in said coil, a storage tank, means for delivering mixed non-condensed vapor and noncondensible gas from said coil to said storage tank, a com' pressor. means for delivering mixed vapor and noncondensible gas from said tank to said compressor. and pressure actuated means for controlling delivery of mixed vapor and gas from said tank to said compressor.

8. In a refrigerating system containing a volatile refrigerant and including a condenser and an evaporator, means for purging the system of noncondensibles and polluting condensibles including a separator structure, a condensing coil in said separator structure, means for delivering noncondensible gas mixed with condensible vapors from the condenser to said coil, means for separating water and liquid refrigerant condensed in said coil, a storage tank, means for delivering mixed non-condensed vapor and noncondensible gas from said coil to said storage tank, a compressor, means for delivering mixed vapor and noncondensible gas from said tank to said compressor, and means for delivering the` and an evaporator, means for purging the systemcompressed mixture from the compressor to said v separator structure for final condensation of any condensible vapor contained in the mixture, means for returning the liquid refrigerant from said separating means into contact with the outside of said coil where it acts as a coolant to condense the condensible vapors passing through the coil.

9. In a refrigerating system containing a volatile refrigerant and including a condenser and anV evaporator, means for purging the system of noncondensibles and polluting condensibles including a separator structure, a condensing coil in said separator structure, means for delivering noncondensible gas mixed with condensible vapors from the condenser to said coil, means for separating water and liquid refrigerant condensed in said coil, a storage tank, means for delivering mixed non-condensed vapor and noncondensible gas from said coil to said storage tank, a compressor, means for'delivering mixed vapor and noncondensible gas from said tank to said compressor, means for deliveringl the compressed mixture from the compressor to said separator structure for final condensation of any condensi-v ble vapor contained in the mixture, and pressure actuated means for controlling delivery of mixed vapor and gas to the compressor from said tank.

10. In a refrigerating system containing a volatile refrigerant and including a condenser of noncondensibles and polluting condensibles including a separator structure, a condensing coilin said separatorstructure, means for delivering noncondensible gas mixed with condensible vapors from the condenservto said coil, means for separating water and liquid refrigerant condensed in vsaid coil, a storage tank, means for delivering mixed non-condensed vaporand noncondensible gas from said coil to said storage tank, a' compressor, means for delivering mixed vapor and noncondensible gas from said tank to said compressor, means for delivering the compressed mixture from the compressor to said separator structure for final' condensation of any condensible vapor contained in the mixture, means for returning the liquid refrigerant from said separating means into contact with the outside of said coil where it acts a a coolant to condense the condensible vapors passing through the coil, andzpressure actuated means for controlling delivery of mixed vapor and gas to said compressor from said tank.

`noncondensibles and polluting condensibles including a separator structure, a vcondensing coil in said separator structure, means for delivering noncondensible gas mixed with condensible vapors from the condenser to said coil, means for separating water and Iliquid refrigerant con'- densed in said coil, a storage tank, means for delivering mixed non-condensed vapor and noncondensible gas from said coil to said storage tank, a compressor, meansfor ydelivering mixed vapor and noncondensible gas from said tank to saidrcompressor for compression thereby, a second condensing coil in said separator struc.- ture, and means for delivering the compressed mixture from said compressor to said second coil for passage therethrough for final condensation of any condensible vapors from the mixture.

12. In arefrigerating system containinga volatile refrigerant and including a condenser and an gas from said coil to said storage tank, a compressor, means for delivering mixed vapor and noncondensible gas from said tank to said compressor for compression thereby, a second condensing coil in said separator structure, means ior` delivering the compressed mixture from said .compressor to said second coil for passage' therethrough for final condensation of lany condensible vapors from the mixture, and means for returning the liquid refrigerant from said separating. I

means into contact with theoutside surfaces of `13. In a refrigerating system containing a volay tile refrigerant and including a condenser and an evaporator, means for purging the system of nonvcondensibles and polluting condensibles including a Separatorr structure, a condensing coil in said separator structure, means for delivering noncondensible vapors from the condenser to-said coil. means for separating water and liquid' refrigerant condensed in said coil, a storage tank,

means for delivering mixed non-condensed vapor and noncondensible gas fromv saidcoi-l to said storage tank, a compressor, means for delivering mixed vapor and noncondensible gas from said tank to said compressor for compression thereby. a second condensing coilin said separator structure/means for delivering 'the compressed mixture from said compressor to said second coil for passage therethrough for nal condensation of any condensible vapors from the mixture, means said coils, where it acts as a coolant to condense .g the condensible vapors passing through the coils.

gas from said coil to said storage tanica compressor, means for delivering mixed vapor and noncondensible gas from said tank to said compressor, means for delivering the compressed mixture from the compressor to said separator structure for final condensation of any condensible vapor contained in the mixture, and means for delivering liquid refrigerant from a predetermined point in the system for contact with the outside of said coil where the liquid refrigerant acts as a coolant to condense the condensible vapors passing through the coil.

16. In a refrigerating system containing a volatile refrigerant and including a condenser and an evaporator, means for purging the system of noncondensibles and polluting condensibles including a separator structure, a condensing coil in said separator structure, means for delivering noncon- .densible gas mixed with condensible vapors from the condenser to said coil, means for separating waterand liquid refrigerant condensed in said coil, means for returning the liquid refrigerant from said separating means into contact with the outside ofthe coil where it acts as a coolant to condense the condensible vapors passing through the coil, and means for delivering liquid refrigerant from said separating means to said evaporator.

17. ,In a lrefrigerating system containing a volatile refrigerant and including a condenser and an evaporator, means for purging the system of noncondensbles and polluting condensibles including a separator structure, a condensing coil in said separator structure, means for delivering noncondensible gas mixed with condensible vapors from the condenser to said coil, means for separating water and liquid refrigerant condensed in said coil, means for returning the liquid refrigfor returning the .liquid-refrigerant from'saidA j separating means into contact with the outside surfaces of said coils whereit acts as a coolant to condense* the condensible vapors passing erant from said separatingfmeans into contact with the outside of the coil where it acts as a coolant to condense the condensible vapors passing through' the coil, and means controlled by variances in the level of liquid refrigerant in the separator for controlling the ow of refrigerant through the coils, and means for delivering liq- Y uid refrigerant froinsald-condenser for contact with theouter surfaces of said coils where it acts as a coolant to condense condensible vaporsv passing through the coils.

14. In a refrigerating system containing a volal f tile refrigerant and including a condenser and an evaporatonmeans forpurging the system of noncondensibles and polluting condensibles including a separator structure, a condensing coil in said separator structure, means for delivering nonoondensible gas mixed with condensible vapors from the condenser to said -coiLmeans for separating watrgand liquid refrigerant `condensed in said coil, andy means'ffor deliveringfliquid refrlgerant from the condenser into contact `with ,l the outside surface of said coil where it actsas acoolanttocondensethe condensiblevapors-passing through the coil.

. a, 15. In a refrigerating system .containing avola.-

v tile refrigerantand includingacondenser and .anff f evapoatonmeanslfor purgin'gthefsystemf'of non- 3 1 conderisibljes'landpolluting.coiidcnsihlcsincluding s .sca Vseparator structure,Yv ac'onden'sng 'coil inaidfy Jse'parator `.st'ri'x'cture'gl' 'means for delivering noni condens'lble g'as. mixed with condensible Avapors from the condenserto" said coil, means for sepa about said coil.

18. In a rt rigerating system containing a volatile refrigerant and including a condenser and an evaporator, means for purging'l the system of noncondensibles and polluting condensibles including a separator. structure, a condensing coil in said said separator structure, means for delivering noncondensible gas mixed with condensible vapors from the condenser to said coil, means for separating water and liquid refrigerant condensed in said coil, a storage tank, means for delivering mixed non-condensed vapor and noncondensible gas from said coil to said storage tank, a com'- pressor,` means for delivering mixed vapor,l and ,noncondensible gas from said tank to said compressor for compression thereby, a second con-v ensingcoil in said separator structure, means liquid'irefrigerant from said separating means into contact with the outside surfaces of said eoils, where it acts as a coolant to condense the rating waterl and. fliquidrefrigerant condensed in said coil, a `storagetank, means for delivering mixed non-condensedvapor and nonconde'nsible condensible vapors passing through the coil, and

. means controlled by variances in the level-of liquid refrigerant in the separating means for` controlling the flow of refrigerant about said coils. j

- .1'9. In a refrigerating system containing. a-vola- .tile refrigerant and including a condenserjand an evaporator, means for purging the systemoi. nonfori'delivering the compressed mixture from said '.,c'ompressor to said second coil for passage therethrough lfor final condensation of any condensible 'vapors from the mixture, means for returning the a 13 condensibles and polluting condensibles including a separator structure, a condensing coil in said separator structure, means for delivering noncondensible gas mixed with condensible vapors from the condenser to said coil, means for separating water and liquid refrigerant condensed in said coil, a storage tank, means for delivering mixed non-condensed vapor and noncondensible gas from said coil to said storage tank, a compressor, means for delivering mixed vapor and noncondensible gas from said tank to said compressor, a second condensing coil in said separator structure, means for delivering` the compressed mixture to said second coil for passage therethrough for final condensation of any con- 14 densible vapors from the mixture, means for returning the liquid refrigerant from said separating means into contact with the outside surv faces of said coils where it acts as a coolant to condense the condensible vapors passing through the coils. and means ,for delivering liquid refrigerant from said condenser for contact with the outer surfaces of said coils where it acts as a No references cited. 

